Rice cookers and slow cookers could not be more different. While they are both common kitchen appliances, they perform very different jobs. The rice cooker cooks rice and steams food very quickly, while the slow cooker stews food for many hours. Neither are really suitable for cooking raw red meats (although slow cookers are often used for this) although that is where their similarity ends.
The main point of confusion between the two appliances arises because the rice cooker generally has a “warm” function. This setting allows cooked food (i.e. rice) to be left for up to 1 hour, sometimes longer, and kept warm in the appliance. This is similar to the slow cooker that slowly stews food and, once cooked, the food can remain for up to 8 hours before being eaten.
Firstly, the main difference between the rice cooker and the slow cooker is the internal temperature. The devices could not be more different, with the rice cooker being designed to rapidly reach boiling point and remain there for a short time cooking the food. While the slow cooker cannot obtain temperatures of more than about 194F (and this high setting is rarely used for prolonged stewing). No “boiling point” is ever reached in the slow cooker.
Secondly, the slow cooker is designed for sustaining a gentle heat for many hours, minimizing energy consumption as it slowly softens the food and warms it through in its cooking process. The rice cooker is designed to draw maximum power for a short amount of time and then the food is cooked and power consumption ended.
Thirdly, the rice cooker and the slow cooker differ in terms of temperature control. Since the rice cooker is a powerful boiling machine, there is no option for controlling temperature. The device is either “on” or “off.” In contrast, the slow cooker makes it possible to set temperature ranges for the internal cooking pot, generally a “high,” “medium” and “low.” The cook must select the appropriate setting for the food.
Lastly, the cooking principles of the two machines differ in that the slow cooker aims to trap any liquids that become vapor allowing them to drip back into the cooking. Nutrients etc. can be reabsorbed into the food. In contrast, the rice cooker releases the steam and vapor that is generated.
In fact, the release of steam is crucial to the operation of the rice cooker. In the rice cooker, the water is brought to boil very fast. Water turns to steam and cooks the rice or steams the vegetables. When the weight in the rice cooker reduces – because of water loss – the pot is lifted off a spring mechanism and the device switches to a “warm” mode. If steam were not lost, the rice cooker would not function.
While rice cookers and slow cookers appear to be very similar kitchen appliances, they are actually totally different in what they are trying to achieve and how they go about achieving that. They should not be confused!